People making the comparison between wow expansions and these doesn't seem to understand one important concept. Wow has a ton of content and a lot of high level gear sets. This game has 1. I don't care if I have to run through them again and get the drop to get the new weapons at the new level. There isn't enough content and there is no incentive to do old raids anymore. If destiny had more content this wouldn't be a conversation, but as it stands the one raid isn't enough especially since there is no pvp gear to get to 32 as well. I don't want to look like everybody else and there is really no way to avoid that unless there is a transmog for old gear. I would say keep upgrading the raids until there are 4 or 5. Then just keep the last two active.